Positive action cam structure for brushmaking machines



July 30, 1968 H. c. PETERSON POSITIVE ACTION CAM STRUCTURE FOR BRUSHMAKING MACHINES Filed April 13, 1966 2 Sheets-Sheet 1 Ju y 3 1958 H. c. PETERSON POSITIVE ACTION CAM STRUCTURE FOR BRUSHMAKING MACHINES 2 Sheets-Sheet 2 Filed April 13, 1966 wart/11111111! United States Patent 3,394,600 POSITIVE ACTION CAM STRUCTURE FOR BRUSHMAKING MACHINES Harold C. Peterson, Geneva, 11]., assignor to Carlson Tool & Machine Co., a corporation of Illinois Filed Apr. 13, 1966, Ser. No. 542,271 Claims. (CI. 7453) ABSTRACT OF THE DISCLOSURE A cam arrangement for transmitting linear motion from rotary motion of a shaft characterized in that cam wheels are spaced apart on a shaft with the peripheries of the cams arranged complementary relative to followers in engagement with each of the cams, the followers being angularly displaced relative to each other so that positive linear motion is always obtained by following engagement of one of the followers on the major portion of one of the cams.

This invention relates to brushmaking machines and more particularly to an improvement in the mechanism of brushmaking machines utilized to drive means for shifting the work bed upon which the brush blank is held.

Typically brushmaking machines are provided with a work table for holding brush blanks during fabricating operations, which is constructed and arranged to move longitudinally and transversely of the machine, as well as vertically. In addition, the brushmaking machine may be provided with fabricating elements, such as drillers and tufters, which are also constructed and arranged to move relative to the Work table in at least one plane during cyclic operation of the machine. Most often this movement is imparted to the several elements of the brushmaking machines through linkage which has a follower element engaging a cam member secured to a rotatably driven shaft. For example, it is common to impart the aforesaid longitudinal or transverse movement to the work table in order to drill and tuft openings along the length or width of a brush blank by securing the table to a linkage member which in turn is driven by a cam member in a forwardly-rearwardly direction responsive to intermittent rotation of a shaft upon which the cam member is mounted. In brushmaking machines for making brush elements, such as push brooms, which may be 18 inches in length or greater, it is necessary that the table be moved back and forth through a relatively lengthy distance in order to accommodate the length of the brush blank itself with intermittent stops at several drilling and tufting stations within the large span of movement. In addition, there must occasionally be intermittent rapid movement of a substantial portion of the overall span of movement. To obtain this action from a cam wheel, it requires that there be a great deal of movement toward and away from the center of the shaft about which the cam is mounted. Typically a follower is formed on an arm which is spring urged toward the cam shaft. In actual experience, it has been found that as the follower moves closer towards the center of the cam or the shaft, the return movement of the linkage under the influence of the spring pulling the follower against the periphery of the cam is not as precise or smooth as desired. This is especially true where a sudden return movement of great magnitude is to be imparted by the follower tracking on a sharp and deep interruption in the cam periphery. Movements out from center or uphill may still be accomplished in a relatively smooth fashion, but the movements toward center or downhill tend to be rough, imprecise, and slightly slower than desirable for optimum performance.

3,394,600 Patented July 30, 1968 It is therefore a general object of this invention to provide a new and improved structure for driving the components of a brushmaking machine.

It is another object of this invention to provide, in a brushmaking machine wherein linear motion is established from a member following the periphery of a rotating cam wheel, structure associated with the cam wheel to afford more positive linear motion toward, as well as away from, the cam wheel.

It is still another object of this invention to provide a cam structure for imparting linear motion to the work table of a brushmaking machine wherein the follower arm associated with the linkage for transmitting the aforesaid linear motion will always be positively urged away from the center of the cam shaft, even when motion towards the cam is to be imparted by the linkage.

Other objects, features and advantages of the present invention will be apparent from the following description of the preferred embodiments illustrated in the accompanying drawings, in which:

FIGURE 1 is a rear elevational view of a brushmaking machine embodying the features of this invention;

FIGURE 2 is a fragmentary broken sectional view taken generally along the line 22 of FIGURE 1 and illustrating in greater detail the features of this invention;

FIGURE 3 is a fragmentary enlarged broken view taken in section along the lines 33 of FIGURE 2;

FIGURE 4 is an enlarged fragmentary view of a portion of the arm on which the cam follower is mounted; and

FIGURE 5 is an enlarged section view taken along the lines 55 of FIGURE 4.

Generally the brushmaking machine shown and disclosed herein is, as to basic construction and principles of operation, of a general type well known in the art. The machine 10 disclosed herein includes a frame or base 12 comprising spaced upright members 14 joined by an upper cross member 15. A work bed or bridge generally indicated as 16 and diagrammatically shown in FIGURE 1 is mounted on the machine for supporting work pieces, such as brush blanks, during operation of the machine. The bed also supports a table 17 (see FIGURE 2) which is mounted for movement longitudinally of the bed on ways 18. Ways 18 are supported on a plurality of slides 19 on ways 20 which extend transversely of the bed. In this manner, the table 17 may be moved at least longitudinally or transversely of the machine.

For providing a source of power to drive the several fabricating components of the brushmaker, the machine is provided with an electric motor 22 mounted on upright motor mount 23. Electric motor 22 drives a pulley or wheel 24 having belt 25 wrapped thereabout which, through suitable linkage and drive train mechanism, well known in the art, drives drilling and tufting apparatus for performing fabricating operations on brush blanks held at fabricating stations on table 17.

Another drive train operably associated with motor 26 includes a belt 27 which drives pulley or wheel 28 on shaft 28a. Belts 29 are wrapped about shaft 28a and about pulley 30, Shaft 31 is eccentrically mounted on pulley 31 and connected to rod 32 for providing intermittent rotation to ratchet 33 by means of pawl 33a. This, in turn, through suitable drive train means intermittently rotates a drive member inside housing 34 to rotate cam shaft 36. A plurality of spiders or wheels 37, 38, 39 and 40 are afiixed to shaft 36 and these wheels, in turn, support cam members 41, 42, 43, and 44, respectively, so that the cams are rotated responsive to rotation of shaft 36. Additional cam members, such as 45, may also be affixed to the shaft.

Shaft 36 is to be given an intermittent step-by-step rotation in timed relationship with the operation of other elements of the brushmaking machine, such as the drilling and tufting elements. For this purpose, suitable clutch and timing mechanism (not shown herein), which is wellknown in the art, will be provided. Therefore, as the shaft 36 is intermittently rotated, the several cams 41 through 45 will be utilized to impart intermittent movement to linkage, which, in turn, will be connected to components of the brushmaking machine for imparting the desired intermittent movement to elements of the brushmaking machine in time with the cyclic operation of the several brush fabricating components of the machine.

As best shown in FIGURE 2, table 17 is provided with an upstanding member 44 to which rod 46 is pivotally secured. At its other end, rod 46 is pivoted to arm 48 through suitable means 50. Arm 48 is bent intermediate its ends as at 52 and is provided with cam follOWers 54 and 56 on either side of the bend. Arm 48 is also pivoted at 58 to a bracket 60 which is secured to portion 62 of the frame of the machine.

In the preferred embodiment, and as shown in FIG- URE 2, the angle of the bend in arm 48 is slightly more than 90 degrees. It is to be further noted that the cam wheels 42 and 43 are mounted on shaft 36 disoriented relative to each other so that the low portion 62 of cam 42 is disoriented relative to the high portion 63 of cam 43 by approximately the same angular displacement that arm 48 is bent at 52. Cams 42 and 43 are intended to be substantially identical so that the magnitude of the distance from the center of shaft 36 to portions of the peripheries of the offset cams in the areas of followers 54 and 56 will always be complementary relative to the sums of the two distances. In other words, one of the followers will always be urged outwardly from shaft 36 a distance substantially equal to the distance which the other follower is encouraged inwardly towards the aforementioned shaft.

In order to accommodate minor differences between the orientation of the earns 42 and 43 and the angular displacement of arm 48, follower 56 is mounted on a yieldable member 64 which is connected to arm 48. Yieldable member 64 is composed of first plate 64a and second plate 64b which is connected to first plate 64 by suitable fastening means 65 to secure the two together as a unit. The first plate is connected to one side of arm 48 by fastening means 66 which establishes a pivotal connection therewith. The second plate 64b is attached to one face of plate 64a so as to be in general alignment with, and form a continuation of, arm 48.

In addition, a generally C-shaped bracket 67 extends about plate 64a and arm 48 and is connected to the top and bottom of arm 48 by suitable fastening means 68. The top and bottoms of the brackets 67 are provided with aligned openings 70 generally in alignment with plate 64a and a set screw 71 is threaded through opening 70 and abuts the bottom of plate 64a. At the top, i

an elongated set screw 72 has its threaded end 73 threadably received in an opening 74 in plate 64a. A spring 75 is positioned between the top of member 67 and a washer 76 positioned to the underside of the head of threaded member 72. It is intended that plate 64a will be slightly narrow in the area of the bracket member 67 as indicated in dotted outline at 77 in FIGURE 4. In this manner, as relative deflections are necessitated between means 64 and arm 48, this can be accommodated by the deflection of plate 64a about pivot 66 against the urging of the strong spring 75. It is to be understood that only minor deflections are expected to be encountered and that this structure is provided for accommodating such minor deflections.

Follower 56 includes a stub 80 having a threaded shank 81 which extends through a slightly arcuate opening 82a in plate 64b and aligned coextensive opening 82b in plate 64a. Lock nuts 83 and 84 are positioned on the stub 80 on each side of plates 64a and 64b to mount the stub so that it projects outwardly from each side a desired distance. In addition, the position of the follower 56 in slots 82a and 82b may be adjusted by means of the set screws 84a which extends through an opening in the side of plate 64b and bears against stub 80. The set screw 84a can be held locked in the desired position of adjustment by lock nut 85. Thus, if it is found that the position of the follower 56 should be changed slightly in order to obtain a more precise movement in the structure, this may be accommodated by moving the follower within slots 82a and 82b and locking the follower in the desired position with set screw 84a and lock nut 85.

In operation, as shaft 36 is intermittently rotated by suitable driving means, arm 48 will be pivoted about stub 58 toward and away from table 17 to move rod 46, and therefore table 17, in a direction away from the shaft 36 as indicated by arrow A in FIGURE 2 and in a direction toward shaft 36 as indicated by arrow B in FIG- URE 2. This will be accomplished by the cams 42 and 43 continually bearing against followers 54 and 56. In FIGURE 2, follower 54 is on the low side of cam 42 or moving toward shaft 36. However, the arm 48 and therefore rod 46 is being given a positive motion by the engagement of follower 56 with the high portion of cam 43. Formerly only one follower on one cam was utilized and the rearward, or movement indicated by arrow B, was obtained by a relatively strong spring pulling in opposition to the peripheral engagement of the cam wheel. It has been found that with the new cam structure of this invention wherein one of the followers will always be urged positively outwardly by the periphery of one of the cam wheels that the motion transmitted through rod 46 is faster and smoother than that possible with the former construction. This, in turn, permits a longer overall stroke to be obtained through rod 46 with more rapid and lengthier stroke changes so that, for example, brush blank structure such as pushbroom units as long as eighteen inches or greater may be made with greater facility. In addition, it has been found that a greater number of holes may be bored in the brush blanks. Moreover, shaft 36 may be operated at a faster speed so that production may be increased. For example, when formerly making pushbroom-type brush structures, the shaft could operate at only revolutions per minute. With the utilization of the cam structure of this invention, and with virtually no other change in the brushmaking machine, it has been found that the shaft 36 can now be operated most efliciently at revolutions per minute and upwardly.

The improvement of this invention is significant in that it not only improves the output of the machine but is done without altering the drive structure of the machine. Rod 46 may be the same structure as utilized in former machines and the cam added to the shaft 36 is virtually a duplicate of the former single drive cam. One further advantage is that the cam wheels may now be formed as substantially smooth discs with only small peripheral interruptions such as 92 in cam 42 and 93 in cam 43 to define the stations of the cam movement.

The foregoing detailed description has been given for clearances of understanding only, and no unnecessary limitations should be understood therefrom, as some modifications may be obvious to those skilled in the art.

I claim:

1. A cam arrangement for transmitting linear motion from a rotating shaft, comprising; a frame; a shaft rotatably mounted in said frame; means for rotating said shaft; a first cam wheel mounted on said shaft for rotation therewith; a second cam wheel mounted on said shaft for rotation therewith; and a follower arm pivoted to the frame adjacent said cam wheels, said arm having a first follower portion in engagement with the periphery of the first cam wheel and a second angularly displaced follower portion in engagement with the periphery of the second cam wheel, the two cam wheels being angularly displaced on the shaft, the displacement being complementary relative to the two followers so as to, in operation, present substantial mirror images of each other whereby pivotal movement of the arm will always be accomplished by positive tracking engagement of one of the rollers with a major portion of the periphery of one of the cams.

2. The cam arrangement of claim 1 wherein the two cam wheels are substantially identical.

3. The cam arrangement of claim 1 wherein one of said follower portions is yieldably associated with the arm to accommodate minor differences in the orientation of the cam wheel and the arm as the cam shaft is rotated.

4. The cam arrangement of claim 3 wherein the yielda'ble mounting of the one follower includes a member pivoted to the arm and normally yield-ably held against movement relative thereto by strong spring means, one of said followers being attached to said pivoted member.

5. A cam arrangement for transmitting linear motion from a rotating shaft, comprising: a frame; a shaft rotatably mounted in said frame; means for rotating said shaft; a first cam wheel mounted on said shaft for rolation therewith; a second cam wheel mounted on said shaft for rotation therewith adjacent said first cam wheel, each said cam wheel having major and minor peripheral portions; and an angular cam arm having first and second portions and being pivoted to the frame in the area of the juncture of the first and second portions adjacent said cam wheel, said arm having a first follower on the first portion thereof in engagement with the periphery of a first cam wheel and a second follower on the second portion thereof in engagement with the periphery of the second cam wheel, the cam wheels and followers being relatively arranged so that the wheels are complementary with respect to the followers, with one of the follower portions being connected to a member yielda'bly pivoted to the arm by spring means, the member having a slot therein in which the follower is mounted by means permitting adjustment of the follower in the slot.

References Cited UNITED STATES PATENTS 1,496,278 6/1924 Schneider 123-90 1,671,973 6/1928 Anderson 12390 2,856,780 10/1958 Hemphill et a]. 74-567 FRED C. MATTERN, 1a., Primary Examiner. W. S. RATLIFF, Assistant Examiner. 

